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  • Writer's picturePoppy

How stress affects immunity

There isn’t one immune support mix I’ve prescribed in the last four months that hasn’t had at least one nervine herb in it. That’s because I know that stress and worry are a huge factor in all my patients’ lives at the moment - and it’s this stress and worry that ultimately causes the immune system to fail when you most need it to be strong and robust.

Yoga is a great way to de-stress and improve immunity

Cortisol and the stress response

Cortisol is well known as the main ‘stress hormone’ in the body - but it does a lot of other things. It’s involved in maintaining blood sugar balance, controlling blood pressure and fighting inflammation, for example.

In fact, the stress response has two distinct arms. In an immediate ‘fight or flight’ response to acute stress - say, a child walks out in front of your car and you swerve or slam on the breaks - adrenaline is the main hormone at play. This gives the body a burst of energy to deal with the immediate situation - your senses become sharper, your pupils dilate, oxygen is sent to the brain, glucose and fats are mobilised from temporary storage sites in the body, and nutrients flood the bloodstream.

Once the initial threat has passed, the adrenaline ‘rush’ subsides. If some level of danger is still perceived, however, the second arm of the stress response is activated - the hypothalamic-pituitary-adrenal (HPA) axis. This sends signals to the adrenal glands to start pumping out cortisol, to maintain the state of alertness. Cortisol shuts down insulin, keeping blood sugar levels high. It also suppresses the immune system by decreasing white blood cell counts - this is how steroids work.

Once again, the effects of cortisol subside when threat is no longer perceived. But what if threats are continuously perceived, multiple times a day, for years and years? In a high-cortisol ‘survival’ mode, the body doesn’t have time to waste on fighting infections, digesting food, or maintaining hormonal and metabolic health.

This system used to serve our ancestors, but it doesn’t work in our modern environments full of different kinds of ‘stressors’. Stress isn’t just emotional or mental - it can be physical or environmental too. Sleep deprivation, poor nutrition, smoking and excess alcohol are good examples of everyday modern stressors that affect immunity in similar ways.

Cortisol and immunity

When you’re chronically stressed, cortisol output is first increased, and then ultimately reduced. Due to its effects on insulin regulation, high levels of cortisol lead to weight gain and metabolic syndrome, and its suppression of normal immune responses leaves you vulnerable to infection.

When levels are too low - caused by a resistance to cortisol created at the cellular level due to chronically high levels over time - the common symptoms will be fatigue, brain fog and inflammatory conditions such as arthritis, psoriasis and inflammatory bowel disease.

The immune system therefore suffers in both scenarios - in one, cortisol is raging through your bloodstream and the power of your immune system to protect you from infection is diminished; in the second, you’ve become desensitised to cortisol over time, losing the ability to adequately fight inflammation in the body.

Both these scenarios are important to consider during a worldwide influenza pandemic - not only do we want our immune systems to be robust and defend us from roaming pathogens, but we also want to be in a state of good health generally. As we know, people with inflammatory conditions like heart disease, diabetes and autoimmune conditions are among the most vulnerable at this time.

So, what is there to do?

Increasing immunity naturally

Look at one ‘stressor’ in your life at a time, and think about how you can decrease it. Are you sleeping enough? Do you drink alcohol every day? Do you eat sweet things on a regular basis? What steps could you take to make your work life less stressful? Take it slow, and you’ll see a marked improvement in your physical and emotional stress levels by focussing on these issues.

Stress reduction practices like yoga, meditation or gardening, and carefully chosen herbal nervines also really help to gain perspective, and motivate you to make some changes. See my next article on nervine herbs for more information on this wonderful class of plant medicines.

Taking steps to decrease physical and mental stress during these critical times is just as, if not more, important in maintaining a strong immune response than taking herbal immune tonics or vitamin D supplements. It’s when you do all of these things together that the magic happens.

Lavender is a great nervine for all ages

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